Yes, I should have noted that the oral (ORS) Radicava form is Part D. But many Part D plans have a specialty drug tier where you pay more of the cost and that require a prior auth, that the ORS form will fall into. Often the specialty tier copays are not capped as they are in other tiers.
Also note the requirements for "continued therapy" (reapproval) for pricey orals like this, are different from initial approval. So to avoid breaks in therapy, you want to make sure the request for continued therapy is submitted showing the criteria have been met, on the schedule required.
I have attached an example of the kind of policy you would want to access on the plan site. Depending on the plan, Radicava could be listed under medical/pharmacy policy, medical policy, or pharmacy policy since it crosses over.